Refrigeration



P. A. NELSON REFRIGERATION May 27, 1941.

Filed Jan.

gmwm 1 BX21 54. Nelson mm Patented May 27, 1941 UNITED. STATES PATENT OFFICE REFRIGERATION rm: A. Nelson, Reno, Nev.

Application January 5, 1939, Serial No. 249,510

1 Claim. (cl. 62-1) This invention relates to an improved apparatus for defrosting a cooling coil and for cooling a receptacle or container by circulating a liquid by an endless route around and through said portions, respectively.

It is a primary object of this invention to provide an endless system for a fluid having means for pumping the fluid or liquid therethrough for defrosting the cooling coils of a cooling unit, for using the fluid cooled by contact with the frost on said coils for cooling an enclosed container and for employing the heat taken up by the fluid in passing through said container to defrost said cooling coils.

It is a particular object of this invention to provide apparatus to recover refrigeration losses caused by excessive frost or ice on cooling coils and other refrigerating surfaces which tend to insulate said coils from the area to be cooled, and transmitting the cooling action of said frost or ice to a zone having a higher temperature and requiring refrigeration.

It is a further aim of the invention to provide a device which may be readily associated with various forms of cooling units and with containers to be cooled without in anywise modifying the refrigerating apparatus of the cooling unit.

Still a further aim of the invention is to provide an endless conduit for defrosting the refrigerating surfaces of a cooling unit having means for by-passing the fluid by a circuitous route around a heating element to more quickly and effectively perform the defrosting operation.

Other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawing, which illustrates a preferred embodiment thereof, and wherein:

Figure l is a side elevational view, partly diagrammatic, showing the preferred form of the apparatus, and

Figure 2 is a similar view showing a slightly modifled form of the apparatus.

Referring more particularly to the drawing, wherein like reference characters designate like or corresponding parts in the different views,-

the device is adapted to be employed in conjunction with any conventional type of cooling unit such for example as a refrigerator, designated l and which is provided with a cooling coil or any other form of refrigerating surface ll through which ammonia or other conventional types of refrigerants are circulated for cooling the refrigerator II, and on which frost or ice will collect requiring defrosting. l2 designates any conven- Gil tional container such as a showcase not provided with a cooling unit but which requires cooling to a temperature higher than the refrigerator ii.

The parts heretofore referred to are of conventional construction and are shown merely to illustrate the application of the apparatus comprising this invention and the method by which tutes the preferred form thereof, the conduit l3 is provided with a portion designated l8 which is disposed within the refrigerator Ill and which is coiled around the convolutions or legs of the cooling coil II. If desired, the portion I6 which is in engagement with the cooling coil H may extend straight along the coil and be welded or otherwise permanently secured thereto instead of being spirally coiled around the portion H, as illustrated. Conduit It also includes the portion I! which is disposed within the case I! and which may be coiled or lapped therethrough, if desired, so that the liquid in passing through portion II will be conveyed by an indirect or circuitous route therethrough. Portions l8 and II are connected by portions l8 and I9, portion l8 communicating with the outlet end of portion l6 and with the inlet end of portion I] while portion i9 ccmmunicateswith the outlet end of portion l1 and the inlet end of portion IS.

A pump 20 of any suitable construction is disposed in portion IQ of the conduit and is adapted to be driven by means of any suitable form of conventional motor 2| .for pumping the liquid heretofore referred to and for circulating it endlessly from the pump 20 around the cooling coil l I back through the casing l2, back through the pum lilfl and thence again around the cooling coil On either side of the pump 20 is disposed a shut-off valve 22 by means of which the fluid heretofore referred to may be retained within the major portion of the conduit I3 should it be necessary to remove the pump 20 so that only that portion of the fluid disposed between the two valves 22 would be lost.

Cooling coil II after being in operation for a short time, particularly where it is necessary to keep the refrigerator I. at a low temperature at about .or below the freezing point, will collect frost which will form a coating around the coil Ill and thereby tend to insulate it and prevent it from properly functioning for cooling the refrigerator III. By operating the motor 2| to drive pump 20 the fiuid with which the conduit I3 is filled will be circulated therethrough and in passing through portion l6 will melt the frost on the coil H and be cooled by contact therewith. This cooled liquid will then pass through portion I8 to portion II which will be at a temperature higher than the temperature of the liquidpassing therethrough due to the fact that the showcase or container I2 is at normal temperature or at a temperature higher than the coil II. The liquid while passing through portion I! will therefore form a refrigerating coil or surface which will cool the case l2 and which will be in turn heated by the temperature therein so that when it again reaches the portion i6 it" will be at a higher temperature to more effectively melt the frost on the cooling coil I I.- It will thus be seen that when the pump 20 is in operation portion l6 will constitute a heating coil of'tubular form through which a heated liquid is being constantly circuthis may be more readily accomplished by shut-- ting valve 24 and the valve 22 adjacent the lated and which has been heated by passing through casing l2 which is at a higher temperature,- while the portion i! will form a cooling coil or pipe line through which a fiuidis being constantly circulated which has been previously precooied by being passed through and around the coollng'means H.

The apparatus employed not only functions as an attachment for cooling units to defrost the refrigerating surfaces thereof while said units are in operation and without effecting the normal operation thereof, but also forms an attachment whereby a conventional cooling unit may be employed to cool a zone or container separate from the container in which the cooling unit is mounted but which requires cooling to a temperature somewhat higher than the temperature of the container in which the 0001- ing unit is disposed.

The apparatus as illustrated in Figure 2 corresponds with the apparatus illustrated in Figure 1 with certain slight modifications which will now be described and which include a bypass designated generally 23 which is connected 'at one end to the portion I8 and at its opposite end to the portion I! so that said by-pass is disposed between portions I6 and" and between the pump 20 and portion l'l. In this modified form of the apparatus a shut-off valve 24 is disposed adjacent the inlet end of portion M I! while the by-pass 23 is provided with shut-off valves 28 adjacent its opposite ends. The intermediate portion of the by-pass 22, between the valves 25, is, coiled spirally around a heating element 26 of any conventional construction which may be heated by any suitable means, not shown, for heating the coiled portion of by-pass 22 and the liquid passing therethrough.

heretofore described. If it is necessaryto completely and quickly defrost the refrigerator ll,

portion l1, and opening both valves 28 after which element 28 is heated in its conventional manner and the pump 2!! put in operation so that the liquid within that portion of the conduit I! which includes portion I78, by-pass 22, and portions II and ll between by-pass 22 and portion I, will be circulated by the pump around a the element 2' to be heated around the coil II and back around the element 28 so that coil II will be very quickly and effectively defrosted.

If desired, motor 2| may be in the form of an electric motor which can be manually operated, by a switch, not shown, or which may be automatically operated by a thermostat and switch, not shown, mounted in casing l2 for cooling this casing when its temperature reaches a predetermined point.

The conduit I! may be formed of a noncorrosive metal and corrosion and electrolysis will be further prevented by the fact that the liquid passing through the conduit does not come in contact with the coil H. Furthermore;

' the liquid in conduit I3 is kept constantly sealed,

- method is employed for adding new units to,

existing refrigerating systems without actually connecting with theconduits of said systems.

. Various modifications and changes in the construction and arrangement of the apparatus are contemplated and may obviously be employed, and the right is therefore expressly reserved to make such variations and changes as do not depart from the spirit and scope of the invention as hereinafter defined by the appended claim.

I claim as my invention:

An endless conduit having a portion coiled around a cooling coil to be defrosted, a heating unit, a portion of said conduit being coiled around saidheating unit, shut-off valves at opposite ends of said last mentioned portion, a bY-Dass around said last mentioned portion extending through an enclosed container, shut-oi! valves at opposite ends of said by-pass, said conduit being adapted to be filled with a liquid having a, low freezing point, and a driven pump disposed in the conduit, between its first mentioned portion and its last mentioned portions, for circulating the liquid through the conduit.

PETER A. NEIBON.

moisture and air and 

